Groups of individuals, such as police officers, firefighters, rescue workers or soldiers, often need to conduct operations in built up urban areas. While operating in such areas, the individuals often find it difficult or impossible to maintain accurate and updated knowledge of one another's locations because the structures in an urban area block visual contact between the individuals. As a result of the inability to establish visual contact, soldiers in urban environments often become casualties of friendly fire. Similarly, police officers, firefighters and soldiers are not able to assist fallen comrades who may be nearby, yet cannot be visually observed.
Current electronic position location systems do not provide a satisfactory solution to the problem of providing an individual, who is part of a group of individuals, with current information as to the positions of other individuals in the group when the individuals of the group are located in an urban environment where visual contact among and between individuals of the group is difficult or not possible. For example, a global positioning satellite (“GPS”) navigational system typically performs poorly inside of a building or in an urban canyon. Similarly, a position determination system for locating cellular phones, such as developed in accordance with the FCC's E911 initiative, is usually inadequate because the positioning information generated is of insufficient accuracy, is limited to a description of location only in two dimensions and depends upon a sophisticated, fixed infrastructure that is not always available in the areas in which many groups will need to conduct operations.
Therefore, a need exists for a system and method for automatically determining the relative positions of individuals who are members of a group without the use of positioning information obtained from an external source that is not part of the group and located remotely from the area in which the group is positioned.